Associated Press

A boost in law enforcement officers on the Standing Rock Indian Reservation has increased the number of arrests.

But some residents worry about what will happen when the short-term surge ends in 90 days.

The Bureau of Indian Affairs put another 24 officers on the reservation June 2.

South Dakota Sen. John Thune says it's an effort to quell juvenile and drug-related offenses where violent crime is six times the national average.

The Republican says part of the long-term answer is an investment in a larger, more permanent law enforcement presence.

He got through the Senate another $40 million to help do that, but the amendment has not passed the House.